fs/gfs2/locking/dlm/thread.c

   1 /*
   2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3  * Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
   4  *
   5  * This copyrighted material is made available to anyone wishing to use,
   6  * modify, copy, or redistribute it subject to the terms and conditions
   7  * of the GNU General Public License version 2.
   8  */
   9
  10 #include "lock_dlm.h"
  11
  12 static inline int no_work(struct gdlm_ls *ls)
  13 {
  14         int ret;
  15
  16         spin_lock(&ls->async_lock);
  17         ret = list_empty(&ls->submit);
  18         spin_unlock(&ls->async_lock);
  19
  20         return ret;
  21 }
  22
  23 static int gdlm_thread(void *data)
  24 {
  25         struct gdlm_ls *ls = (struct gdlm_ls *) data;
  26         struct gdlm_lock *lp = NULL;
  27
  28         while (!kthread_should_stop()) {
  29                 wait_event_interruptible(ls->thread_wait,
  30                                 !no_work(ls) || kthread_should_stop());
  31
  32                 spin_lock(&ls->async_lock);
  33
  34                 if (!list_empty(&ls->submit)) {
  35                         lp = list_entry(ls->submit.next, struct gdlm_lock,
  36                                         delay_list);
  37                         list_del_init(&lp->delay_list);
  38                         spin_unlock(&ls->async_lock);
  39                         gdlm_do_lock(lp);
  40                         spin_lock(&ls->async_lock);
  41                 }
  42                 spin_unlock(&ls->async_lock);
  43         }
  44
  45         return 0;
  46 }
  47
  48 int gdlm_init_threads(struct gdlm_ls *ls)
  49 {
  50         struct task_struct *p;
  51         int error;
  52
  53         p = kthread_run(gdlm_thread, ls, "lock_dlm");
  54         error = IS_ERR(p);
  55         if (error) {
  56                 log_error("can't start lock_dlm thread %d", error);
  57                 return error;
  58         }
  59         ls->thread = p;
  60
  61         return 0;
  62 }
  63
  64 void gdlm_release_threads(struct gdlm_ls *ls)
  65 {
  66         kthread_stop(ls->thread);
  67 }
  68